The present disclosure relates generally to semiconductor processing equipment and more specifically to a gas box for delivering contaminant-free, precisely metered quantities of process and purge gases to a semiconductor process reaction chamber. More particularly, the present disclosure relates to a manifold for interchangeable use as part of a modular gas box system.
Various recipes are used in the fabrication of semiconductor devices. Such fabrication involves many discrete processing steps where a silicon wafer is cleaned, polished, oxidized, masked, etched, doped, metalized, etc. The steps used, their particular sequence and the materials involved all contribute to the making of particular devices. The fabrication of a single chip can require the careful synchronization and measured delivery of as many as a dozen gases to a reaction chamber.
Accordingly, wafer fabrication facilities are commonly organized to include areas in which chemical vapor deposition, plasma deposition, plasma etching, sputtering and other similar manufacturing processes are carried out. The processing tools, be they chemical vapor deposition reactors, vacuum sputtering machines, plasma etchers or plasma enhanced chemical vapor deposition, must be supplied with various process gases. Pure gases must be supplied to the tools in contaminant-free, precisely metered quantities.
In a typical wafer fabrication facility the gases are stored in tanks, which are connected via piping or conduit to a gas box. The gas box is used to deliver contaminant-free, precisely metered quantities of pure inert or reactant gases from the tanks of the fabrication facility to a process tool. The gas box includes a plurality of gas paths having gas control components, such as valves, pressure regulators and transducers, mass flow controllers and filters/purifiers. Each gas path has its own inlet for connection to separate sources of gas, but all of the gas paths converge into a single outlet for connection to the process tool.
In order to reduce losses associated with semi-conductor processing tool down time for equipment repair or cleaning, there has always been a desire for gas boxes having components that are easily and quickly reconfigured or replaced. In this vein, modular gas boxes modular having components and even whole gas paths that are relatively easy to interchange and replace have been provide.
U.S. Pat. No. 5,992,463 (the ""463 patent), for example, shows a modular gas box system including a plurality of gas paths in the form of gas stick assemblies comprising one-piece gas manifolds and gas components mounted on the manifolds. The manifolds are arranged to receive gas at an inlet end, and pass the gas along a plurality of interior channels to a plurality of component receiving stations, and ultimately through a single outlet of the manifold.
The modular gas box system shown in the ""463 patent is easier to manufacture than many previous gas boxes, since standardized manifolds having standardized footprints are incorporated in the gas box. The component receiving stations of the substantially rectangular one-piece manifolds are positioned along a top surface of the manifold and the components received thereon communicate with a gas directing passageways defined within the manifolds.
The ""463 patent provides many benefits in that each manifold is a standardized, prefabricated component. In addition, there is no necessity to provide welded connections or connectors directly to the gas components, as required by most previous gas box systems, since all connections are made through and supported by the manifolds. The modular gas box system shown in the ""463 patent can be easily reconfigured by a user in the field, as welds and other connections need not be broken. A gas controlling or monitoring component may be replaced or added simply by disconnecting the component from the manifold.
While the modular gas box system shown in the ""463 patent provides great advantages over the prior art gas boxes, there is still desired an improved modular gas box system. More particularly, there is still desired an improved manifold for use as part of a modular gas box system.
Accordingly, the present disclosure provides a gas manifold for a modular gas box system for delivering contaminant-free, precisely metered quantities of process and purge gases to a semiconductor process reaction chamber. The manifold includes a surface, a manifold port in the surface, and at least one station in the surface for receiving gas controlling and gas monitoring components. The station includes an inwardly facing side wall extending into the manifold from the surface to a base of the station. The base is divided into a central portion and an outer portion, the central portion having a first station port, and one of the outer portion of the base and the side wall having a second station port. An internal gas passageway of the manifold connects the manifold port to one of the first and the second station ports.
The manifold provides the benefit of allowing the use of a standard annular gasket or o-ring between the first and the second station ports. These and other advantages of the present disclosure will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiment which is illustrated in the drawing figures.